Heat oven to 350°F. Line two baking sheets with parchment paper.

In a large bowl, whisk together flour, ground ginger, cinnamon, allspice, cardamom, nutmeg and salt until well combined.

In the bowl of a food processor, pulse 1/4 cup powdered sugar and pecans together until a coarse meal forms. 

In the bowl of a stand mixer fitted with the paddle attachment or in a large bowl using an electric hand mixer, beat butter and vanilla on medium-high speed until creamy, about 2 minutes. Beat in nut mixture until just combined. Stir in flour mixture until just combined. Dough will be moist but crumbly.

Turn dough out onto a clean countertop; knead a few times to form a ball. Gently but firmly press dough ball into a rough log shape.

Use a sharp knife to cut dough into 24 equal-sized pieces. Roll each piece into a 1 1/2-inch log, then bend to form a crescent shape, tapering ends slightly. Place on prepared baking sheets spaced at least 1 inch apart.

Bake cookies 12 to 15 minutes, rotating pans halfway through, until cookies are set and bottoms are golden-brown. Cool on baking sheets 2 minutes, then transfer to a cooling rack.

In a small shallow bowl, sift remaining 1/2 cup powdered sugar. Roll still-warm cookies in powdered sugar, then return to cooling rack to cool completely. Roll or dust fully cooled cookies with any extra powdered sugar.

Store fully cooled cookies in an airtight container at room temperature for up to 5 days.